It has been long recognized that in certain vehicles it is necessary to have an adjustable console to allow the operator thereof to adjust the console for his particular needs when operating the vehicle. Typically, the pedestal console moves forwardly and rearwardly relative to an operator's seat. In most cases, the operator's seat is also highly adjustable to further allow the operator to customize the relation for his particular requirements.
Various arrangements have been proposed for locking of the pedestal console in one of a host of positions and these structures include both mechanical locking arrangements and hydraulic locking arrangements.
In some applications, such as motor graders, in addition to being able to provide a high degree of flexibility to allow the operator to adjust the operating position, there is a requirement to provide good visibility either side of the console to allow effective operation of the grader. Grader cabs normally have very large windows at the front and in the doors of the cab to allow the operator to view the operating area about the grader, and in particular the blade position.
A typical adjustable control console is shown in U.S. Pat. No. 3,737,003. This particular design uses a mechanical latching arrangement. Other designs have used a hydraulic locking arrangement where a piston and cylinder having a valve to allow hydraulic fluid to flow from one side of the piston to the other when the valve is opened, and essentially lock the piston relative to the cylinder when the valve is closed. Some of these designs have also accommodated the mechanical linkage arrangement between the various actuators pivotally mounted on a shaft, which cooperate with a bell cranks adjacent the base of the control console.
The prior art approaches are more complicated than required and are often difficult to service. In particular, adjustment of the linkages at the base of the pedestal can be awkward.